Internally driven scratch brush



R. F. CHRISTIAN INTERNALLY DRIVEN SCRATCH BRUSH A riLZOQ 1965 Filed July15, 1963 6 Sheets-Sheet 1 FIG 4A 1 9 r if,

v INVENTOR. m

ROBERT F. CHR is-riAN ATTOR IVE) April 20, 1965 R. F. CHRISTIANINTERNALLY DRIVEN SCRATCH BRUSH 6 Sheets-Sheet 2 Filed July 15. 1963/7////// r/////////4 ////////w///W///////- I INVENTOR ROBERT F.CHRis-riAN A'I'ToRN EV April 20, 1965 Filed July 15, 1963 R. F.CHRISTIAN INTERNALLY DRIVEN SCRATCH BRUSH 6 Sheets-Sheet 3 IwvawronRoam-r F. CHR isTiA ATTORNEY April 20, 1965 R. F. CHRISTIAN INTERNALLYDRIVEN SCRATCH BRUSH 6 Sheets-Sheet 6 Filed July 15, 1963 FIG. 6.

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N r M M K T my J TM R E wi United States Patent 3,173,744 INTERNALLYDRIVEN SCRATCH BRUSH Robert F. Christian, World Trade Center, SanFrancisco 11, Calif. Filed July 15, 1963, Ser. No. 295,652 8 Claims.(Cl. --21) The present invention relates to scratch brushes.

Scratch brushes may be used for various purposes and a particular use isto remove scale particles which adhere to work rolls of rolling millswhen aluminum plate is being rolled between them.

When an aluminum strip passes between work rolls scale particles adhereto the work rolls, and are removed by brushes and pressure jets so thatwork rolls continuously present clean work faces to the strip. Thisstrip passes through a number of such roll pairs and is progressivelyreduced in thickness and is increased in width. This strip comes out ofa furnace at a temperature exceeding 700 F. As it contacts the workrolls, it reduces in temperature and transfers much of its heat to thework rolls. It follows that the work rolls operate at varioustemperatures varying from as high as 600 F. at the first stand, to aslow as 200 F. to 300 F. at the last roll pair.

As the work rolls contact the sheet, large quantities of scale adhere tothe faces of these work rolls, which scale must be continuously removedto prevent imbedding into or scarring of the aluminum strip. This isaccomplished by scratch brushes and jet streams of soluble oil andwater. The solution is mostly caught up in gutter and what falls on thestrip is blown oil? by compressed air, and the solution from the lowerbrush is caught in a lower gutter not shown.

Rotary cylindrical scratch brushes relatively smaller in diameter to thework rolls, usually rotate at a pcripheral speed of 4,000 f.p.m. (feetper minute) counter directionally and many times faster in surface speedthan the surface speed of the work rolls. This brush action generateshigh temperature in the bristles which is partially absorbed by thesolution, but solution temperature is of the order of 140 F. Thesebrushes are also at times arranged to axially reciprocate with a strokeaction up to 1" while rotating. Heretofore, it has been customary todrive these brushes from a prime mover (of the order of to H.P.),through a speed reducer and chain drive to an extended shaft on thebrush cylinder adapted to be driven. Other drive arrangements have beenused, such as bevel gearing.

Depending on operating conditions, it is sometimes important to maintainuniform brush pressure and accurate alignment of the brush to the workroll. At other times it is desirable to vary the axial alignment of thebrush and the work roll, and have variable brush pressures across theface of the work roll. The life of the brush and the quality of aluminumstrip, are dependent upon these features. It is obvious that theserequirements, together with very limited available space, impose severehandicaps on the drives presently being used.

It has been found that the kind of drive arrangement, presently beingused, involved as it is with the varying requirements of alignment andbrush pressure, has been expensive, of great bulk, complicated indesign, and resultant in shortened brush life, increased maintenance,and has a direct bearing on the quality of the strip. Vibrations andcertain unbalances associated with this drive are suspected of causingsomewhat mysterious ghost" patterns in the strip.

It should be mentioned that these brushes operate flooded with jets ofWater soluble oil, at a rate of about 500 gallons per minute tofacilitate removal of the scale particles from the bristles. Thus theall-exposed parts of the drive mechanism and the associated adjustmentmechanism are subject to flooded operating condition that is mostundesirable, and results in high cost of maintenance. Furthermore, theperiodic adjustment of the brush to the roll requires constant andcareful realignment of the separate entities of the drive mechanism.

Furthermore, from such drives there is a considerable loss of power intransmission from the motor to the brush contactsas much as 40% Anobject of the present invention is to provide a scratch brush assemblyof compact design thus eliminating the chain drive or bevel gearingdrive and minimising the vibrations, unbalances and power losses of suchdrives.

A further object of the invention is to provide a scratch brush assemblywherein the prime mover is not exposed to the jet streams from thepressure jets.

Another object is to provide a scratch brush assembly wherein the brushmay easily be adjusted.

An embodiment of the invention will now be described by way of examplewith reference to the accompanying drawing, wherein,

FiGURES 1A, 1B, 1C, together form a sectional elevation of a scratchbrush assembly made in accordance with the invention,

FIGURE 2 is a sectional elevation taken on line AA of FIGURE 1, and

FIGURES 3 and 4 show a method of mounting the brush assembly at the endsthereof;

FZGURE 5 shows an alternative method of mounting the brush assembly; and

FTGURE 6 is an enlarged sectional elevation of part of the scratch brushassembly.

A specially constructed wire bristle assembly 2 comprising a channelsection formed to crimp the bristles U shape, is spirally wound about atubular mandel 1.

At the starting end 3 the winding is attached to a flange 4 whichcomprises an extended portion of the bearing cage 1%. As shown in FIGURE6, the flange 4 is grooved and the channel section or horseshoe shapedmetal base Ztll extends into the groove and is held therein by a setscrew 203. Preferably three set screws 203 are used to pinch the end ofthe channel section 201. The flange 4 is secured to the body of themandrel by set screws 202 that are also in the spiral groove. Four setscrews 202 are preferably used. The bristles are trimmed oif as at 204to permit a balancing collar to be slipped over the flange and thisbalancing collar is prevented from slipping off by set screws 265 thatenter into the spiral groove of the flange. The winding terminates at 5where it may be attached to a sliding ring 6 by means similar to thoseshown in FIGURE 6. Another ring 7 is attached to the end cage 11 in amanner that permits it be screwed on to ring 6 so that the lattercompresses the bristle assembly 2. The ring 7 is threaded opposite handto the hand of the spiral bristle assembly. Sliding ring 6 hasserrations (not shown) that engage the bristles of the assembly justabove the channel section in such a manner as to hold the end of thebristle winding from escapement. Ring 7 has a plurality of drilled holeswhich can be used in conjunction with a spanner wrench to tighten thisring in the threads, and these holes 8 also serve to receive lead plugsas required to accurately, dynamically, and statically balance themandrel 1. A similar group of holes are provided in flange 4 for similaruse in balancing.

The mandrel 1 is arranged for rotation on bearing cage 10 at one end,and on bearing cage 11 at the opposite end. Bearing cages 1i) and 11 areeach provided with several ports MA and 11A respectively, for ingressand according to the temperature of the operating conditions and thehorsepower of the prime mover, and may be air, circulating water, oroil.

In tie preferred form of the invention shown in FIG flow vane fanassembly 12, comprising a motor, and a fan, and a housing having adeflected portion 13, direct ing the air through a' plurality of axialslots 14, through an annulus for-med between theouter tubular housing 16of the prime mover and the inner'wall of the m'andrel 1. I

i URE 1 air enters through ports 11A flowing into'an axial. r

This oil drains via tube 400 into a central bore 40D in the motor shaft21. and flows through to lubricate bearing 23 an'd by tube 46E tobearing 30. A second portion of the gear housing 44 is secured to 40 bybolts 45 and sup- The annulus is a space between a stationary wall 16 Iand the rotating wall 1. This feature, cooperating with the fan,produces an axial turbulent' scrubbing type of air circulation (or wateror other medium if employed),

to extract from and through this annulus the'rnaximum amount of heat. Intheannulus the total outside diameter of the motor shell has beenmachined with a threading tool at 17A to create extended surface area.

Coolant can pass through the annulus 15, and through passages 18surrounding a reduction gear. These passages are of larger crosssectional area than the annulus, since the gear reduction housing ispreferably approxi: mately elliptical in shape, ratherthan circular. antcontinues through, and exits through the ports 10A. If a liquid coolantis used rather than oil, the motor, reduction gear, etc, are tightlysealed to prevent the liquid entering them, the fan is omitted, and theflow is regu- 20 The cool- I lated in volume so as not to unbalance therotation of the mandrel. g

The prime mover 19 is preferably an AC. squirrel cage motor with a rotor29 built on to a tubular shaft 21 that is coaxial with the mandrel 1 andis journalled on ball bearings 22 and 23 with seals 22A and 23A. Bearing22 a The motor stator is held from rotation by a tubular support ortorque tube 25 into which is assembled the axial flow fan assembly 12.This torquetube varies in length according to the length of the mandreland bristle assembly which is in the order of from 72" to 120" inoverall length.

The torquetube 25 is secured to a fixed mounting or carrier. This has arim portion 27 on which this torque tube 25 seats and a wall portion 28with ports for air circulation and a shaft portion 29 which carries'theball bearing 30. Suitable double lip seals 31 and 32 are provided.

Since shaft 29 and associated. carrier parts are secured to torque tube25 which in turn is secured to the tubular housing or wall' 16, theseparts are non-rotating, and the mandrel .1 rotated at this end onbearing over shaft portion 29 as a fixed shaft. Shaft portion 29 istubular and has a threaded plug 54A in one end thereof. The leads frommotor 19 and the leads from axial flow fan motor egress through tubularportion of 29 for connection to power source. The portion 29 is mountedin a mounting block 29A to which it is keyed by key 29B.

At the gear end of the prime mover. is a reduction gear comprising afirst pinion or gear 33 which" is preferably an integral part of shaft21. A countershaft 34 is designed as a cluster, one portion being. apinion 35 meshing with pinion 33. Another portion is a pinion 36meshports bearings 46 and 47 for shaft'38; vShaft 38 is drilled andflared, coaxial with shaft 48 which-is closed with a threaded plug 54.This passage isfo-r filling or drainage of lubricant by lube gun orsuction. The gear case lubricant will also provide lubrication for theball bear- ,ingsand spline connection.

The rotatable driveshaft 3 8 ends at spline 39. Qty axially, but. spacedtherefrom is shaft 48 fixed against rotation by block 49-whichis of thesame design as 29A both being rectangular and each bored and keyed onthecenterline, and each with twocavities. Shaft 48 extends within and outof themandrel, and supports part 10 for rotation on bearings50 and 51within the mandrel. These bearings are double lip sealed by seals 52.

The scratch brush assembly is a self-contained'unit and I only'thenon-rotatable shafts at each end project beyond the overalllength of thebrush and flanges. These shafts maybe mounted on suitable slide andprovided with screws .of hydraulic cylinders for applying brush pressureagainst the work rolls in the preferred amount of pressureor'inisalignment desired; while at the times the internal mechanism ismaintained in line, and can be suitably ventilated and cooled.

ing with a pinion 37. Pinion 37 is integral'with a rnain noted Theassembly contains four gears, a male and female spline and nine ballbearings which are all lubricated from one central oil supply in thegear case thus eliminating grease-lubrication which is an advantagesince oil runs cooler than grease. V V FIGURES 3 and 4 show the methodof mounting the brush roll at the ends thereof.

A rectangular frame 101 suitably bolted together, has two slots 102 and103: for receiving trunnions 102A, 103A from part 29A or 49 (FIG. 1) ina manner that permits part 2A or 49-to position itself according to howthe brush face may be misaligned with the work roll face. Part 29A (and49) has upper and lower cavities and is connected in the lower cavitywith a clevis 104 to a hydraulic cylinder 105 having a body clevis 106secured to frame 101. The part 29A has a gasketed cover plate 107 overthe other cavity containing the motor terminals, and in thiscavity themotor leads. can be connected to power source such as a flexible conduit108 which will compensate for movement of part 29A or 49 in the frame101. The motor leads come out only at part 29A so that one cavity inpart 49 is not used. I

Frame 101 is secured to a structural frame to support the brush forrotation and adjustment.

An alternate type of mounting is shown in FIGURE 5. The assembly asshown in FIGURE 3 is mounted in a sub-frame 110 surrounding it, andsupported therein by trunnionsrlltlA, 110B with ball bearings, and arocker shaft 112 in bearings 113 which are secured. to a structuralframe 114 for rotation and adjustment. Oneof these frames is connectedto an eccentric drive (not shown) which can be actuated to rock thewhole assembly axially to give a horizontal axial reciprocating brushaction againstthe work rolls. 7

It is of'utmost importance to suitVopera-ting conditions that the brushdiameter be kept to a minimum and normally in the order of 14- to 15" indiameter. The length 5 of the br'ush'is on theor'der of from 66" to longto su t the production requirements of the aluminum sheet.

The main tubular membenthere'fore, is designed with a heavy wall forminimum deflection" in operating conditio'ns, and to permit'maximumadjustment in the pressure of the bristles against the work-drum withoutdistortion of the tubular member.. The bristles in the brush are usually.014 dia. high tempered wire, and the bristles are assembled in thebrush extremely close together, giving a brush of great density. Sincethe brush is rotating at a speed much higher than the surface speed ofthe work rolls, and normally in opposite direction to them, it requiresconsiderable horsepower and develops considerable heat.

The power required for a brush approximately 6 Wide, rotating at 3,000f.p.m. is on the order of 25 HP. Since the brush is only 14 to 15" indiameter and is mounted on a heavy wall tube, the inside diameter of thetube to receive the motor is relatively small. The problem has been topack HP. or more into a minimum of diameter and still have a passageleft for clearance and ventilation for the removal of the heat from themotor. Incorporated in the motor structure is a high capacity axial flowfan, with its own special motor, so designed to force the air throughthe annulus between the motor and tube. The motor assembly is heldstationary within the tube and the power takeoff shaft of the motortransmits the power through suitable coaxial reduction gearing to drivethe rotating tube at the desired peripheral speedfrom 700 to 900r.p.-rn.

The motor assembly is water-tight so that if desired, the axial flow fancan be omitted, and a stream of Water for cooling can be passed throughthe tube (via the two hollow shafts) to keep the motor and reductiongearing cool. The sealing arrangement being so designed as to isolateall bearings, gears, spline, wiring, etc., from water or oil if used ascoolant. Some cooling comes from the flooded operation of the brushitself. As it has heretofore been mentioned, a stream of as much as 500gallons of water a minute is on these brushes and this, of course, keepsthe bristles cool and keeps the temperature of the tube itself at a lowpoint; something on the order of 135. It is also possible to cool thismotor by putting compressed air through the tube and around the motor,entering the air and taking it out via the same hollow shafts.Supplementing the cooling by the axial fiow fan, and/ or air or waterflow, the motor itself, can be specially insulated to safely operate attemperature up to 300 F. Note that it is even possible to pump lube oilthrough all the bearings and gear reduction via the removable plug onthe ends. In the taps for these plugs eyebolts can be inserted forlighting.

It will be seen from the foregoing description that this assemblycomprises a permanently aligned mechanism and that the alignment of themotor in relation to the tube and the speed reducer is not affected bythe alignment, or misalignment of the brush assembly to conform with thework roll face. The adjustment of the brush bristles to the Work rollface can be either on sliding blocks or on a suitable frame that canpivot, thus swinging the motor through an arc. No misalignment of theinternal parts of this mechanism is possible by the adjustment of thebrush to the work roll face.

I claim:

1. A brush assembly comprising a tubular mandrel, a bristle assemblysecured to the mandrel, a prime mover means mounted Within the tubularmandrel, said prime mover having a stator and a driven shaft, speedtransforming means mounted within the mandrel and connecting the primemover driven shaft drivably to the mandrel, end bearing means supportingthe mandrel rotatably at its ends, a tubular support within the mandrelconnected at one end to the bearing means at one end of the mandrel, aprime mover housing within the mandrel and carrying the prime moverstator and fixed at one end to the other end of said tubular support, atubular gear housing Within the mandrel and connected at one end to theprime mover housing, said gear housing containing said speedtransforming means, said tubular support, prime mover housing and gearhousing together forming a fixed tubular member, bearings mounted insaid fixed tubular member carrying the prime mover 6 driven shaft, saidspeed transforming means including an output shaft, and bearings carriedby said fixed tubular member and carrying said output shaft rotatably.

2. A rotary tool assembly comprising a tubular mandrel, cleaning meanssecured to the mandrel, an electric motor mounted within the tubularmandrel, said electric motor having a stator and a driven shaft, a speedreduction gear mounted Within the mandrel and connecting the electricmotor driven shaft drivably to the mandrel, end bearing means supportingthe mandrel rotatably at its ends, a tubular support within the mandrelconnected at one end to the bearing means at one end of the mandrel, anelectric motor housing Within the mandrel and fixed at one end to theother end of said tubular support, an electric motor in the electrichousing, a tubular gear housing within the mandrel and connected at oneend to the electric motor housing, said gear housing containing saidspeed reduction gear, said tubular support, motor housing and gearhousing together forming a fixed tubular member spaced radially from themandrel, said speed reduction gear including an output shaft, andbearings carried by said fixed tubular member and carrying said outputshaft rotatably, a bearing member located within said fixed tubularmember, a first bearing carried by said bearing member and supportingone end of the motor driven shaft, a second bearing carried by the gearhousing and supporting the other end of the motor driven shaft, endbearing cages fixed to the mandrel at the ends thereof and mounted onsaid end bearing means respectively, one of said end bearing meanshaving two bearings spaced apart Within and carrying the adjacent endcage.

3. A rotary tool assembly comprising a tubular mandrel, cleaning meanssecured to the mandrel, an electric motor mounted within the tubularmandrel, said electric motor having a stator and a driven shaft, a speedreduction gear mounted Within the mandrel and connecting the electricmotor driven shaft drivably to the mandrel, hearing means supporting themandrel rotatably at its ends, a tubular support within the mandrelconnected at one end to the bearing means at one end of the mandrel, anelectric motor housing within the mandrel and fixed at one end to theother end of said tubular support, an electric motor within saidelectric motor housing, a tubular gear housing within the mandrel andconnected at one end to the motor housing, said gear housing containingsaid speed reduction gear, said tubular support, motor housing and gearhousing together forming a fixed tubular member, bearings mounted insaid fixed tubular member carrying the electric motor shaft, said speedreduction gear having an output shaft, a countershaft having pinionteeth on each end thereof, pinion teeth on the motor shaft meshing withthe pinion teeth on one end of the countershaft, pinion teeth on saidoutput shaft meshing with the pinion teeth on the other end of thecountershaft, splines on the output shaft, internal splines on one ofsaid cages engaging the splines 0n the output shaft, and bearingscarried by said fixed tubular member and carrying said output shaftrotatably.

4. An internally powered scratch brush as claimed in claim 3 wherein anaxial flow vane fan assembly is mounted in the tubular support.

5. A brush assembly comprising a tubular mandrel, a bristle assemblysecured to the mandrel, an electric motor mounted within the tubularmandrel, said electric motor having a stator and a driven shaft, a speedreducing gear connecting the motor driven shaft drivably to the mandrel,end cages secured to the ends of the mandrel respectively, bearing meanssupporting the end cages rotatably, a tubular support within themandrel, a mo tor housing within the mandrel containing the motor andfixed at one end to the other end of said tubular support, a tubulargear housing within the mandrel and connected at one end to the motorhousing, said gear housing containing said speed reduction gear, saidtubur 3;? lar support, motor housing and gear housing-together forming afixed tubularmember spaced radially from f the mandrel, hearings mountedin said fixed tubular mem- 4 her carrying the motor shaft, said speedreduction gear 'havingan output shaft, bearings carried by said fixedtubular member and carrying said output shaft rotatably,

openings in ,said cages, a fan Within said tubularsupv the slots. 1

port, and openings in the tubularsupport, whereby the fan draws. air inthrough the openings in 'one cage and impels it through the openings inthe tubular's uppo'rt then through the space between the tubular supportand the mandrel, and out through the openings in the other cage.

6. A scratch brush as jclaimed-in claim 1, having oil seals at the endsof the prime mover shaft between the shaft and the fixed tubularjmember, a reservoir adjacent the speed transforming means, in which oilflung off by the gears is caught, a tube conducting oil from thereservoir into the motor shaft which is tubular so that the oil can passinto the shaft at one end thereof through the seal of the other endthereof, and means to conduct the mandrel and said'frames having slotsto receive said,

trunnions, said trunnions being positioned in a horizontal plane andmounted in the slots for vertical movement and means for each frameconnecting the frame adjustnbly to the adjacent trunnions, saidmeansbeing adjustable radially of the mandrel'to adjust the trunnionsalong the oil leaving the shaft to the adjacent end bearing means. 7 r

7. A brush assembly comprising a tubular mandrel,

a bristle assembly secured to the mandrel, a prime mover means mountedwithin the tubular mandreL'speed transforming means connecting the primemover drivably to the mandrel, bearing means supporting the mandrelrotatably at its ends, shafts carrying said bearing means, trunnions onthe shafts, two frames one at each end of the mandrel and said frameshaving slots to'receive said trunnions, said 'trunnions being positionedin a horizontal plane and mounted in the slots for vertical movement andmeans for each frame connecting the frame adjjust the slots, two shaftsmounted one at each end of the mandrel, trunnions on each frame at'rightangles to the bearing means trunnions, brackets on each shaft carryingthe frame trunnions.

References Cited by the Examiner V UNITED STATES PATENTS 1,480,542

1/24 Brown 15-213 X 1,678,064 7/28 Jones etal. IS-21.3 1,770,643 7/ 30Giambertoni 15-49. 2,281,256 4/42 Bargfeldt et al. 15-77 2,856,624 10/58Cook et'al. 15-181 3,084,367 4/63, ,Radinse 15-181 FHOREIGN PATENTS j846,333' 8/52 Germany.

CHARLES A. \VILLMUTH, Primary Examiner.

1. A BRUSH ASSEMBLY COMPRISING A TUBULAR MANDREL, A BRISTLE ASSEMBLYSECURED TO THE MANDREL, A PRIME MOVER MEANS MOUNTED WITHIN THE TUBULARMANDREL, SAID PRIME MOVER HAVING A STATOR AND A DRIVEN SHAFT, SPEEDTRANSFORMING MEANS MOUNTED WITHIN THE MANDREL AND CONNECTING THE PRIMEMOVER DRIVEN SHAFT DRIVABLY TO THE MANDREL, END BEARING MEANS SUPPORTINGTHE MANDREL ROTATABLY AT ITS ENDS, A TUBULAR SUPPORT WITHIN THE MANDRELCONNECTED AT ONE END TO THE BEARING MEANS AT ONE END OF THE MANDREL, APRIME MOVER HOUSING WITHIN THE MANDREL AND CARRYING THE PRIME MOVERRSTATOR AND FIXED AT ONE END TO THE OTHER END OF SAID TUBULAR SUPPORT, ATUBULAR GEAR HOUSING WITHIN THE MANDREL AND CONNECTED AT ONE END TO THEPRIME MOVER HOUSING, SAID GEAR HOUSING CONTAINING SAID SPEEDTRANSFORMING MEANS, SAID TUBULAR SUP-